1. Field of the Invention
The present invention relates to systems which transport flat materials such as metallic strips through strip mills, and more particularly to such systems which include devices for controlling the direction of travel of these flat materials as they move towards the strip mill coilers.
2. The Prior Art
Metallic strip materials are conventionally fabricated in strip mills by a process which includes heating the slab of metallic material from which the strips are to be made in a furnace, finish rolling the slabs to form the metallic strips in a mill train, and winding the strips on a coiler which is positioned at the end of the mill train. A feed guide is normally positioned in front of the coiler so as to center the leading end of the metallic strip as it approaches the reeling mandrel of the coiler. The feed guide is important because if the leading end of the metallic strip is not properly positioned as it contacts the reeling mandrel, it will not be properly wound around the coiler.
Conventional feed guides include two guide boards which are adjusted to form a funnel-shaped space therebetween so as to direct a metallic strip entering its wider end in exact fashion towards the reeling mandrel. These feed guides have been quite satisfactory when dealing with relatively thick hot-rolled metallic strips. However, when the hot-rolled strips are relatively thin, e.g., less than 2.5 mm in thickness, the feed guides may not properly act to center the strip. In this regard, hot-rolled metallic strips which are relatively thin may not have a uniform thickness when they leave the roll stands and the leading end may be curved out of the plane of the remainder of the strip (this portion being called the "initial curve" of the strip). In addition, the thin hot-rolled strips may easily become displaced from the center of the rollers over which they pass towards the feed guide, and, if too far off-center at the point of their entry into the funnel-shaped space in the feed guide such that their leading end impacts at an angle against the guide boards, their leading end, instead of being shifted in position, will flip over. The remainder of the strip material, being nevertheless pushed forward, will thereafter become folded in an accordion-like fashion. All of this strip material will thus become unusable. Further, since modern strip mills operate at very high rolling speeds, the following strips may become damaged as well, requiring their being also discarded. Obviously this waste is quite uneconomical.
Thus, it is an object of the present invention to provide an improved transport system for conveying flat materials, e.g., thin hot-rolled metallic strips, through a strip mill wherein the direction of movement of the leading end of the flat material (and thus the entire piece of flat material) can be effectively adjusted.